textproduct: Rapid City

KEY MESSAGES

- Cooler this week with precipitation chances through mid-week.

- Near-freezing to freezing overnight temperatures possible beginning Monday night.

- Breezy tonight into Monday; watching high wind potential for Thursday/Friday.

DISCUSSION

(This Evening Through Sunday) Issued at 1249 PM MDT Sun Oct 11 2026

Upper level analysis and water vapor imagery show closed upper low over northeastern OR/southeastern WA with trough axis extending southward. Broad upper level ascent continues to overspread the Northern Plains as moisture streams into the region. The surface cold front settled south of the forecast area and stretches from upper MN through southeastern SD into NE. Considerable cloud cover persists over the forecast area; have dropped high temperatures to account with most areas (especially along and north of I90) struggling to push out of the 50s today. Increasing chances of rain later this afternoon through the overnight hours as better upper level ascent overspreads the area, although heaviest precipitation amounts will remain north of the forecast area.

Winds will turn northwesterly Monday with gusts around 40 mph across the western SD plains as secondary front pushes south of the area. Upper level low will slowly eject from the Four Corners region late Tuesday into Wednesday with additional precipitation chances, although better chances of appreciable precipitation amounts will remain south of the CWA. Cooler air will linger through the week with a threat of near-freezing to freezing temperatures possible each night Monday night through the week.

The NBM continues to show wind gusts exceeding 60 mph across northwestern SD and portions of the western SD plains Thursday afternoon and evening. However, ensemble guidance is not supportive, with low probabilities of high winds (EPS generally ~40-50% probability of exceeding 40 mph) and many members (EPS/GEFS) peaking well below 45 mph. Current thinking is that the most favorable ingredients and strongest winds will remain displaced to our east, although confidence is low given the large ensemble spreads.

Upper ridge is forecast to build over the western US by the end of the week into next weekend with temperatures trending above average and a return of elevated fire weather conditions.

AVIATION

(For the 18Z TAFS Through 18Z Monday) Issued At 1110 AM MDT Sun Oct 11 2026

MVFR to local IFR ceilings will persist over parts of northeastern Wyoming and northwestern South Dakota today into tomorrow. Scattered showers will also be possible across much of the region this evening and into the overnight hours, with local MVFR conditions possible in the heavier showers. Winds will veer around to the southeast through the period ahead of the next wave. Easterly upslope flow will support patchy fog and MVFR to local IFR ceilings on the northwestern South Dakota plains and along the eastern Black Hills foothills tonight into tomorrow morning.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.